Django

===========================

*March 4, 2024*

Django 3.2.25 fixes a security issue with severity "moderate" and a regression
in 3.2.24.

CVE-2024-27351: Potential regular expression denial-of-service in ``django.utils.text.Truncator.words()``
=========================================================================================================

``django.utils.text.Truncator.words()`` method (with ``html=True``) and
:tfilter:`truncatewords_html` template filter were subject to a potential
regular expression denial-of-service attack using a suitably crafted string
(follow up to :cve:`2019-14232` and :cve:`2023-43665`).

Bugfixes
========

* Fixed a regression in Django 3.2.24 where ``intcomma`` template filter could
return a leading comma for string representation of floats (:ticket:`35172`).


===========================

===========================

*February 6, 2024*

Django 3.2.24 fixes a security issue with severity "moderate" in 3.2.23.

CVE-2024-24680: Potential denial-of-service in ``intcomma`` template filter
===========================================================================

The ``intcomma`` template filter was subject to a potential denial-of-service
attack when used with very long strings.


===========================

===========================

*November 1, 2023*

Django 3.2.23 fixes a security issue with severity "moderate" in 3.2.22.

CVE-2023-46695: Potential denial of service vulnerability in ``UsernameField`` on Windows
=========================================================================================

The :func:`NFKC normalization <python:unicodedata.normalize>` is slow on
Windows. As a consequence, ``django.contrib.auth.forms.UsernameField`` was
subject to a potential denial of service attack via certain inputs with a very
large number of Unicode characters.

In order to avoid the vulnerability, invalid values longer than
``UsernameField.max_length`` are no longer normalized, since they cannot pass
validation anyway.


===========================

===========================

*October 4, 2023*

Django 3.2.22 fixes a security issue with severity "moderate" in 3.2.21.

CVE-2023-43665: Denial-of-service possibility in ``django.utils.text.Truncator``
================================================================================

Following the fix for :cve:`2019-14232`, the regular expressions used in the
implementation of ``django.utils.text.Truncator``'s ``chars()`` and ``words()``
methods (with ``html=True``) were revised and improved. However, these regular
expressions still exhibited linear backtracking complexity, so when given a
very long, potentially malformed HTML input, the evaluation would still be
slow, leading to a potential denial of service vulnerability.

The ``chars()`` and ``words()`` methods are used to implement the
:tfilter:`truncatechars_html` and :tfilter:`truncatewords_html` template
filters, which were thus also vulnerable.

The input processed by ``Truncator``, when operating in HTML mode, has been
limited to the first five million characters in order to avoid potential
performance and memory issues.


===========================

===========================

*September 4, 2023*

Django 3.2.21 fixes a security issue with severity "moderate" in 3.2.20.

CVE-2023-41164: Potential denial of service vulnerability in ``django.utils.encoding.uri_to_iri()``
===================================================================================================

``django.utils.encoding.uri_to_iri()`` was subject to potential denial of
service attack via certain inputs with a very large number of Unicode
characters.


===========================

===========================

*July 3, 2023*

Django 3.2.20 fixes a security issue with severity "moderate" in 3.2.19.

CVE-2023-36053: Potential regular expression denial of service vulnerability in ``EmailValidator``/``URLValidator``
===================================================================================================================

``EmailValidator`` and ``URLValidator`` were subject to potential regular
expression denial of service attack via a very large number of domain name
labels of emails and URLs.


===========================